Gastrointestinal irritation caffeine

Caffeine is a powerful stimulant of central nervous system and also stimulates the cardiac muscle. However, high amounts of the alkaloid have noticeable irritation of gastrointestinal tract as well causes matw unwanted effects [1]. 

Some people find that caffeine irritates their gastrointestinal tract. It is still unclear if the effect is from caffeine itself, or from another as-yet-undetermined substance that could be in coffee. Regardless, people with stomach ulcers or irritation may not find relief by switching from caffeinated to decaffeinated coffee. 

For most young people, indulgence in caffeine as a mind drug is pleasant, but overindulgence can exacerbate insomnia, cardiovascular and gastrointestinal problems, and anxiety. Caffeine is so irritating to the stomach that many people who drink coffee have indigestion most of the time. —... 

Note that decaffeinated coffee is not inert. In addition to small amounts of caffeine (enough to stimulate sensitive individuals), it contains other active substances from the coffee bean that can be irritating to the nervous, gastrointestinal, cardiovascular, and urinary systems. This is true of water-processed decaf, as well as die less safe solvent-extracted brands, which may contain residues of toxic chemicals. 

Caffeine intoxication is the only official diagnosis associated with caffeinism in the DSM-IV-TR. Caffeine-induced anxiety may manifest as restlessness, nervousness, excitement, insomnia, diuresis, flushing, gastrointestinal disturbance, muscle twitching, irritability, and jitteriness. If caffeine-induced insomnia requires specific treatment, caffeine-induced sleep disorder (DSM-IV-TR) is an appropriate diagnosis." ... 

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